Reciprocating engine



June 1 1926.

M. L. DAVIS, JR RECIPROCATING ENG INE 4 Sheets-Sheet 1 l/WE/VTUI? 111mm{EM B 7 Emma 3 Filed Feb. 28, 1922 June 1 1926.

M. L. DAVlS, JR

RECIPROCATING ENGINE Filed Feb. 28, 1922 4 Sheets-Sheet 2 .\NQ I: I,

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M. 1... DAVIS, JR

RECIPRQCATING ENGINE Filed Feb. 28', 1922 4 Sheets5heet 4 INVENTOR IllPatented June 1, 1926.

warren "starts MATTHEW L. DAVIS, JR, F OAK GROVE, ALABAMA.

RECIPROCATING ENGINE.

Application filed February 28, 1922. Serial No. 540,011.

This invention relates to compound ongines and has been developed withparticular reference to engines .in which the power is taken from one ofthe pistons through longitudinal slots in the cylinder, the steam beingadmitted alternately at opposite ends of the cylinderin which the pistonmoves. In accordance with the invention the high pressure cylinder ismounted within the low pressure cylinder and itself const1tutes the lowpressure piston. The placing of the high pressure cylinder within tl elow pres sure cylinder makes the engine exceedingly compact, does awaywith the necessity of jacketing the high pressure cylmder, permits thesteam leads, especially of the exhaust steam from the high pressurecylinder into the low pressure cylinder, to he very direct, andgenerally contributes to increased efliciency. Suitable provisions,which may be varied in engines adapted for different uses, are made forthe control of the admission and discharge of the steam or other motivefluid to and from the several cylinders and for the operative connectionof the several pistons with the crank shaft or driven memher. Theinvention will be explained more fully hereinafter with reference to theaccompanying drawings in which it is illustrated in practical embodimentand in which Figure 1 is a top view of an engine which is constructed inaccordance with the invention.

Figure 2 is a view thereof in side elevation.

Figure 8 is a view in end elevation as seen from the right hand inFigure 2.

Figure 4 is a partial section on the plane indicatedby the broken line4ll of Figure 1 and on a slightly larger scale.

Figures 5, 6, 7 and 8 are respectively detail views in section on theplanes indicated by the broken lines 5+5, 66, 77 and 8-8 of Figure 4,Figure 8 not being afull section.

The low pressure cylinder, crank shaft and other working parts of theengine are shown as mounted on a suitable supporting frame a, the enginebeing represented in this in stance as a horizontal engine. The lowpressure cylinder 7) is shown as steam jacketed, having a surroundingchamber'b' to which the exhaust steam is admitted as hereinafterexplained and from which the exhaust steam escapes through a suitableconnection, as

at If. The low pressure piston in this in stance is constituted by thehigh pressure cylinder. The exhaust steam is discharged from the lowpressure cylinder through suit able ports Z1 and oscillating valves 12operated as hereinafter described. The ends of the cylinder Z) areclosed by heads 5 to which fi'irther reference will be made. i

The high pressure cylinder 0 is placed centrally within the low pressurecylinder 6 and, in the construction shown, is movable longitudinallytherein, constituting, with its heads 0, the low pressure piston.Between the inner and outer walls 0 and c ofthe combined high pressurecylinder and low pressure piston are steam chambers 0 separated by atransverse wall 0 provided with ports 0, through which steam is admittedto the high pressure cylinder, other chambers 0 which receive the valves0 which control the exhaust from the high pressure cylinder into thesteam chamber 0", and other chambers 0 which receive the valves 0 whichcontrol the admission of steam from the steam chamber 0 to the lowpressure cylinder b. The valves 0 and 0 respectively have slidingengagement with oscillating shafts 0 and 0 which are mounted in theheads 72 and are actuated as hereinafter described.

W ithin the high pressure cylinder 0 is the high pressure piston clwhich is connected by a piston rod (5, cross-head d and pitman (Z withthe high pressure crank pin 6 of the crank shaft 6. i

The high pressure cylinder 0, which also servesas the low pressurepiston, has at diametrically opposite points studs 7 whichprojectthrough longitudinal slots 6 in the low pressure cylinder 7), the slotsbeing formed between the ends of the low pressure cylinder and of suchlength that while permitting the full stroke of the high pressurepiston, they are lapped by such piston in all positions thereof, thepiston being in the nature of a trunk piston for the purpose just statedas well as for the purpose of receiving or constituting the highpressure cylinder. The studs or projections f are connected by pitmen fwith the corresponding crank pins 0 of the crank shaft 0.

High pressure steam is admitted, at each end of the compound cylinderstructure, through an inlet 9 an oscillating valve g and a straight tube9, into the corresponding steam chamher ca tube 9 is fixed in thecorresponding head 5 of the low pressure cylinder and passes through astuffing box in the corresponding head 0 of the combined high pressurecylinder and low pressure piston into the corresponding steam chamber 0the tubes being of such length that each is always in engagement withthe corresponding head 0 and permits the full stroke of the pistonwithout disengagement.

From each chamber 0 the steam, admitted under control of the oscillatingvalve 9', passes through the port 0 into the correspending end of thehigh pressure cylinder 0 and against the corresponding face of the highpressure piston (Z. The exhaust steam from the high pressure cylinderpasses, under control of the oscillating valve 0 in the valve chamber 0into the steam chamber 0 from which it passes through the valve chamber0 under control of the oscillating valve 0 and through the head 0 intothe corresponding end of the low pressure cylinder Z), to exert itsforce against the corresponding face of the combined piston and cylinder0. The exhaust steam from the low pressure cylinder passes through therespective ports 5 under the control of the oscillating valves 6 intothe steam jacket Z) and thence through the outlet 6 Any convenientformof valve gearing may be provided for the operation of the severalvalves. As shown, a gear a on the crank shaft 6 meshes with a gear h ona lay shat't it. Through bevel gears 72, the lay shaft it drives a shaft7L which, through eccentrics h and suitable linkage 7L operates theoscillating valves 0 and 0 An eccentrio in on the shatth, throughsuitable linkage If, operates the oscillating valves Z9 It will beunderstood that the steam leads, the valves, and the valve gearing aresubstantially of ordinary construction and arrangement and may be variedto suit different conditions of use, as may also other details ofconstruction and arrangement, the invention, except as pointed out inthe claims, not being limited to the particular construction andarrangement shown and described.

I claim as my invention:

1; In an engine, the combination of a low pressure cylinder, a highpressure cylinder placed within the low pressure cylinder and movabletherein and having a head to fit within the low pressure cylinder andhaving a steam chamber in communication with the interior of the highpressure cylinder, and a high pressure steam inlet pipe fixed in thehead of the low pressure cylinder and extended through the head of thehigh pressure cylinder into said steam chamber.

2. In an engine, the combination of a low pressure cylinder, a highpressure cylinder placed within the low pressure cylinder and movabletherein and having a head to fit within the low pressure cylinder andhaving a steam chamber in communication with the interior of the highpressure cylinder, a high pressure steam inlet pipe fixed in the head ofthe low pressure cylinder and extended with a sliding fit through thehead or the high pressure cylinder into said steam chamber, and means toadmit and control the passage of exhaust steam from the high pressurecylinder into the low pressure cylinder.

3. In an engine, the combination of a low pressure cylinder, a highpressure cylinder placed within the low pressure cylinder and movabletherein and having a head to fit within the low pressure cylinder, andhaving a steam chamber in communication with the interior of the highpressure cylinder, a high pressure steam inlet pipe fixed in the head ofthe low pressure cylinder and extended with a sliding fit through thehead of the high pressure cylinder into said steam chamber, a secondsteam chamber in communication with the interior of the high pressurecylinder and in communication with the interior of the low pressurecylinder, means to admit and control the passage of high pressure steamto the first named steam chamber, and means to admit i and control thepassage of exhaust steam from the high pressure cylinder to the secondnamed steam chamber and from the second named steam chamber to the lowpressure cylinder.

' 4. In an engine, the combination of a low pressure cylinder, a highpressure cylinder placed within the low pressure cylinder and movabletherein and having a head to fit within the low pressure cylinder, andhaving a steam chamber in communication with the interior of the highpressure cylinder, a high pressure steam inlet pipe fixed in the head ofthe low pressure cylinder and extended with a sliding fit through thehead of the high pressure cylinder into said steam chamber, a secondsteam chamber in communication with the interior of the high pressurecylinder and in communication with the interior of the low pressurecylinder, means to admit and control the passage of high pressure steamto the first mentioned steam chamber, an oscillating valve carried bythe head of the high pressure cylinder to control the passage of steamfrom the high pressure cylinder to said second named steam chamber, andan oscillatingshaft mounted in the head of the high pressure cylinderand having a sliding engagement with said valve.

5. In an engine, the combination of a low pressure cylinder, a highpressure cylinder placed within the low pressure cylinder and movabletherein and having a head to fit within the low pressure cylinder, andhaving a steam chamber in communication with the interior of the highpressure cylinder, a

high pressure steam inlet pipe fixed in the head of the low pressurecylinde' and on tended with a sliding fit through the head of the highpressure cylinder into said steam chamber, a second steam chamber incommunication with the interior oi": the high pressure cylinder and incommunication with the interior of the low pressure cylinder, means toadmit and control the passage of high pressure steam to the firstmentioned steam chamber, an oscillating; valve to control the passage ofsteam from said second named steam chamber to the low pressure cylinderand an oscillating shaft mounted in the head of the low pressurecylinder and having a sliding engagement with said valve.

6. In an engine, the combination of a low pressure cylinder, a highpressure cylinder placed within the low pressure cylinder and movabletherein and having a head to lit within the low pressure cylinder, andhaving a steam chamber in communication with the interior of the highpressure cylinder, a high pressure steam inlet pipe lined in the head ofthe low pressure cylinder and extended with a sliding lit through thehead of the high pressure cylinder into said steam chamber, a secondsteam chamber in communication with the interior of the high pressurecvlinder and in communication with the interior of the low pressurecylinder, an-

oscillating valve to control the passage of exhauststeam from saidsecond named steam chamber to the low pressure cylinder, and anoscillating shaft mounted in the head of the low pressure cylinder andhaving a sliding engagement With said valve.

7. In an engine, the combination of a low pressure cylinder, a highpressure cylinder placed within the low pressure cylinder and movabletherein and having a head to tit within the low pressure cylinder, andhaving a steam chamber in communication With the interior of the highpressure cylinder, a high pressure steam inlet pipe fixed in the head ofthe low pressure cylinder and eX- tended with a sliding fit through thehead of the high pressure cylinder into said steam chamber, a secondstean'i chamber in com munication with the interior of the high pressurecylinder and in communication with the interior of the low pressurecylinder, an oscillating valve to control the passage of steam from thehigh pressure cylinder to said second named steam chamber, anoscillating valve to control the passage of steam from said second namedsteam cham her to the low pressure cylinder, and oscillating shaftsmounted in the head of the low pressure cylinder and having slidingengagen'ient with said valves.

This specificatioi-i signed this 24th day of February A. D. 1922.

MATTHEW L. DAvis, JR.

